/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

package com.zhs.gccs.utils.zip.extra;

import java.util.zip.ZipException;

/**
 * This is a class that has been made significantly smaller (deleted a bunch of
 * methods) and originally is from the Apache Ant Project
 * (http://ant.apache.org), org.apache.tools.zip package. All license and other
 * documentation is intact.
 * 
 * General format of extra field data.
 * 
 * <p>
 * Extra fields usually appear twice per file, once in the local file data and
 * once in the central directory. Usually they are the same, but they don't have
 * to be. {@link java.util.zip.ZipOutputStream java.util.zip.ZipOutputStream}
 * will only use the local file data in both places.
 * </p>
 * 
 */
public interface ZipExtraField {

	/**
	 * The Header-ID.
	 * 
	 * @return the header id
	 * @since 1.1
	 */
	ZipShort getHeaderId();

	/**
	 * Length of the extra field in the local file data - without Header-ID or
	 * length specifier.
	 * 
	 * @return the length of the field in the local file data
	 * @since 1.1
	 */
	ZipShort getLocalFileDataLength();

	/**
	 * Length of the extra field in the central directory - without Header-ID or
	 * length specifier.
	 * 
	 * @return the length of the field in the central directory
	 * @since 1.1
	 */
	ZipShort getCentralDirectoryLength();

	/**
	 * The actual data to put into local file data - without Header-ID or length
	 * specifier.
	 * 
	 * @return the data
	 * @since 1.1
	 */
	byte[] getLocalFileDataData();

	/**
	 * The actual data to put into central directory - without Header-ID or
	 * length specifier.
	 * 
	 * @return the data
	 * @since 1.1
	 */
	byte[] getCentralDirectoryData();

	/**
	 * Populate data from this array as if it was in local file data.
	 * 
	 * @param data
	 *            an array of bytes
	 * @param offset
	 *            the start offset
	 * @param length
	 *            the number of bytes in the array from offset
	 * 
	 * @since 1.1
	 * @throws ZipException
	 *             on error
	 */
	void parseFromLocalFileData(byte[] data, int offset, int length) throws ZipException;
}
